JPS62288877A - Condensed dew removing device for copying machine - Google Patents

Abstract

PURPOSE:To reduce the cost required for condensed dew removal, by rotating a photosensitive body for a fixed time or fixed distance and removing condensed dew by using a cleaning blade when it is detected by a thermistor that the room temperature is lower than a prescribed temperature after a fixed time has passed from the power supply start. CONSTITUTION:Since the median of fixing temperature data CR3 obtained by a three-times-readable fixing thermistor 14 after a fixed time has passed from the turning on of a heater after starting power supply is reliable as the room temperature, there is a fair chance of condensing dew when the median is lower than the set temperature of a fixing temperature data buffer. Therefore, a photosensitive body 4 and developing sleeve roller 7 are rotated and the surface of the photosensitive body 4 is cleaned with a cleaning blade 10 and, if dew is condensed on the surface, the dew is removed. Therefore, no special parts are required for condensed dew moval and the constitution can be made simple. Accordingly, the cost required for condensed dew removal is reduced.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Technical Field) The present invention relates to a dew condensation removal device for a copying machine, and more particularly, to a copying machine having a cleaning blade for removing toner on a photoreceptor. It is applied to the machine.

(Prior Art) Conventionally, when a copying machine is started, especially when copying is performed immediately after starting heating in winter, an abnormal image appears. This is due to the difference in heat capacity between the air and the photoconductor, developing sleeve, etc. that make up the copying machine, resulting in a difference in the startup time at room temperature and the startup time for heating the photoconductor, developing sleeve, etc. get up. That is, even though the air is warm, the photoreceptor, developing sleeve, etc. are cold, so dew condensation occurs on the photoreceptor and the developing sleeve, which interferes with the normal transfer operation.

Therefore, in order to prevent the above-mentioned dew condensation, there is an example of using a heat retaining heater such as a cement resistor, but although this cement resistor is relatively inexpensive, its effect of preventing dew condensation is not sufficient. In addition, to increase the effect of preventing condensation, the power is increased,
There is a method of controlling using a thermistor or a dew condensation sensor, but either method increases the cost.

(Objective) It is an object of the present invention to provide a dew condensation removing device that eliminates the problems of the prior art described above and can reliably remove dew condensation at low cost.

(Structure) In order to achieve the above object, the present invention provides a copying machine having at least one thermistor for temperature control and a cleaning blade for removing toner on a photoreceptor after transfer. , when the thermistor detects that the room temperature is lower than a predetermined temperature after a predetermined period of time after the power is turned on, the photoreceptor is rotated for a predetermined time or a predetermined distance, and the cleaning blade removes condensation. .

Hereinafter, a detailed explanation will be given based on one embodiment of the present invention.

FIG. 1 is a schematic diagram showing an example of a copying machine to which the present invention can be applied, in which a document table 2 and a contact glass 3 are provided on the upper part of a main body 1, and a photoreceptor belt 4 is disposed inside. An exposure lamp 5 consisting of a fluorescent lamp is provided around the circumference of the photoreceptor belt 4.
and an eraser unit with built-in fluorescent lamp heater/thermistor 5a and vertical grain sensor 6a) 6. Current (11 sleeve roller 7,
Registration roller pair 8. Transfer charger9. A cleaning blade 10 and the like for removing the toner on the photoreceptor 4 after transfer is arranged, and a conveyor belt 12. Fixing rotor pair with built-in fixing heater 13. A fixing thermistor 14 and the like are arranged.

Each of the above-mentioned parts is controlled by the control system shown in FIG. That is, the one-chip CPU (central processing unit) 15 includes the fluorescent lamp heater and thermistor 5.
A or a detection signal from a temperature detection element such as the fixing thermistor 14 is input, and a dip switch 169 such as a test mode switch 16a or a free run switch 16b is input.
, the on/off signal of the countdown switch 16c is input, and the offset master 17. A signal from the seam sensor 6a in the eraser unit and various inputs 18 are input.

Furthermore, in response to the above-mentioned input signals, the CPU 15 drives the main motor 20. Optical system drive solenoid 21. Optical system stop solenoid 22. It drives various loads 23, connects to various reset circuits 24, and exchanges input and output with the operating section 25.

The above embodiment will be explained in more detail with reference to the flowcharts shown in FIGS. 3 to 9.

When the power is turned on, the main routine power-on shown in FIG. 3 begins. Then, first, the memory element of the CPU 15, RA
Initialize CPU 5, such as clearing M (3-1), and then set the subroutine pointer to initial mode (3-2). Then, the subroutine to be executed next according to the set subroutine pointer (
4) from the table and jump to that subroutine (3-3). In this example, a jump is made to the initial mode subroutine shown in FIG.

In Figure 7, the A/D port input is first read (7-1), but since the sensor output is still unstable because the power is turned on, the counter 26 (7-2) buys time and stabilizes. Read the A/D input, set the mode using dip switch I6 (7-3), check the on status of various sensors on the paper feed conveyance path, and check for jams (7-3).
-4), set the subroutine pointer to the test mode for now 7-5), and if the test mode switch 16a is on, (3) in the flowchart of FIG.
-3) Return to test mode 7-6) If off, move the subroutine pointer from test mode to W
Reset to T mode (described later) (7-7) and go to initial mode set (7-8). Here, the copy set number counter is set to 1, and the ADS element is turned on, page continuous copying is performed, the specified page display is turned off, the manual feed interrupt display is turned off, and the copy sheet number counter and the copy output sheet number counter are cleared. Next, set the FFUSIL flag immediately after the power is turned on (7-9), and return to the state (3-3) in Fig. 3 described above.
Jump to the A/D port interrupt subroutine shown in the figure.

In FIG. 9, first, the A/D port interrupt timing timer 27 is used to go to the next step every 11.3 milliseconds, for example.
9-1), otherwise the process returns to the state of (3-3) in FIG. 3 and proceeds to the photoreceptor pre-rotation control subroutine shown in FIG. 8, which will be described later. Next, A/D boat read timer 2
If the reading counter 28 is 1, the fixing temperature data CR3 from the fixing thermistor 14 is transferred to the fixing temperature data buffer (1). 29th time) 29 Hesdo Shikaku 9
-5), then transfer the fluorescent lamp beater temperature data CRz from thermistor 5 to the fluorescent lamp heater temperature data buffer (first time)
At 9-6>, the process returns to the state (3-3) in FIG. 3 and proceeds to the subroutine in FIG. 8, which will be described later. Further, when the third degree reading counter 28 is 2, the fixing temperature data C
R3 is stored in the fixing temperature data buffer (second time) 29 9-8), then the fluorescent lamp heater temperature data CRz is stored in the fluorescent lamp heater temperature data buffer (2nd time) 30 9-9), and ( Return to 3-3) and proceed to the next subroutine shown in FIG. When the 3rd reading counter 28 is other than 2, clear this counter 28 (9-10),
Save the fixing temperature data CR1 to the fixing temperature data buffer (3rd time) 29 to 9-11), store the fluorescent lamp heater temperature data CR to the fluorescent lamp heater temperature data buffer (3rd time) to 30 to 9-12), until now. The first to third data of the fixing temperature data buffer 29 and the first data of the fluorescent lamp heater temperature data buffer 30
9-13), and return the respective median values to the fixing temperature data buffer 29 and fluorescent lamp heater temperature data buffer 30 to the state of (3-3) in FIG. Go to the subroutine in Figure 8 (
.

The photoreceptor pre-rotation control subroutine shown in FIG. 8 is the most characteristic part of this embodiment. In the same figure, check the flag (FFUSIL) immediately after power-on (8-1
). This flag is set only for 200 milliseconds after the power is turned on by the flag reset timer 31 immediately after the next power is turned on (8-2). While this flag is set, the fixing heater control (5-2) shown in Figure 5 and the fluorescent lamp heater control (6-2) shown in Figure 6 are not performed, and the thermistor detected temperature is It can be considered approximately room temperature.

If the room temperature is predicted from the detected temperature a certain period of time after the heater is turned on, the error in the input voltage is directly reflected in the detected temperature, resulting in poor accuracy. Also, if it takes 200 milliseconds, the A/D port reading subroutine shown in Figure 9 will be enough.
The median value of the fixing temperature data CR1 obtained by the fixing thermistor 14 can be read as the room temperature, and the warm-up time will not be affected in this short period of time. Here, the fixing temperature data CR, is the set temperature (10 in this embodiment) at the fixing temperature data buffer (median value) 29.
℃) or below, there may be condensation (8-
4) Set the photoconductor rotation flag (FOPCON) 8-5) Go to check the photoconductor rotation flag (FOPCON) (8-6) Here, set the flag (FOPCON)
If not set, the process returns to the state (3-3) in FIG. 3 and goes to the subroutine shown in FIG.

Further, when the flag (FOPCON) is set, in this embodiment, the main motor 2 is operated to rotate the photoreceptor 4 and the developing sleeve roller 7 shown in FIGS. 1 and 2.
0 (8-8), and pull the optical system drive solenoid 21 and optical system stop solenoid 22 so that the drive is not transmitted to the optical system scanner that is synchronized with the main motor 20 (8-7).

In this embodiment, since the photoreceptor 4 with an end belt is used, the seam sensor 6a is checked (8-9), and the belt rotation check counter 32 counts that the photoreceptor 4 has rotated four times (8-9). -11), reset the optical system drive solenoid 21 and optical system stop solenoid 22.
-12), stop the main motor 20 (8-13), and reset the 5-light body rotation flag (FOP CON).
-14), return to (3-3) in FIG. 3, and proceed to the next subroutine shown in FIG.

Then, according to the subroutine search (3-3) in Figure 3,
The process advances to the fixing heater control subroutine in FIG. 5, the fluorescent lamp heater control subroutine in FIG. 6, and then to the WT mode subroutine, where it is determined whether to search the WT mode table again or go to another mode table.

In this embodiment, as described above, the photoreceptor 4 and the developing sleeve roller 7 are rotated when there is a possibility of dew condensation.
The cleaning blade 10 cleans the surface of the photoreceptor 4, and when there is dew condensation, the dew condensation can be removed.

In the above embodiment, the photoreceptor 4 and the developing sleeve roller 7
Although the photoreceptor 4 is rotated, only the photoreceptor 4 may be rotated.

Furthermore, it goes without saying that the comparison (8-3) with the set temperature in FIG. 8 can be performed based on the value of the fluorescent lamp heater temperature data buffer 30.

(Effects) As explained above, the present invention predicts the state of dew condensation, rotates the photoreceptor, and removes condensation using a cleaning blade, thereby eliminating the need for any special parts for removing condensation and having a simple configuration. It is possible to provide a simple and cost-reduced dew removal device for a copying machine.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a front view showing an outline of the copying machine, FIG. 2 is a schematic diagram explaining the control system, and FIG. 3 is a schematic diagram showing the control system.
4, 5, 6, 7, 8, and 9 are flowcharts in this embodiment. 4... Photoreceptor, 5a, 14... Thermistor, 10.
...Cleaning blade, 15...CPU, 29,
30...Temperature data buffer, CR2, CR3...
Temperature data. Figure 2 Figure 3

Claims (1)

[Claims] In a copying machine that has at least one thermistor for temperature control and a cleaning blade for removing toner on the photoreceptor after transfer, the room temperature is set to a predetermined level by the thermistor after a certain period of time after power is turned on. A dew condensation removal device for a copying machine, characterized in that when a temperature is detected to be lower than the temperature, the photoreceptor is rotated for a predetermined time or a predetermined distance, and dew condensation is removed by the cleaning blade.